Relationship between Coronary Circulation and Myocardial Function in the Right Heart

研究了冠状动脉灌注压与右室游离壁局部心肌功能的关系，在13例开放性心脏病患者中，用颈动脉分流术灌注右冠状动脉，用声测微技术测量不同灌注水平下右室游离壁收缩期缩短当冠状动脉灌注压力或流量高于31 mm Hg或0.27 ml/min/g时，区域缩短对冠状动脉灌注压力或流量不敏感。一旦冠状动脉灌注低于此临界水平，基底至心尖和周向方向的区域缩短均线性下降，这取决于灌注压力的程度。尽管冠状动脉灌注压或流量与区域缩短之间存在单指数关系，但灌注压和流量之间始终存在直接线性关系，无论是否存在肺动脉条带，提示右冠状动脉血流的自动调节是有限的，维持右室局部心肌功能的临界灌注压高度依赖于右室收缩压的水平。右室收缩压是冠脉灌注不足时局部室壁运动的重要决定因素之一。

The relationship between coronary perfusion pressure and regional myocardial performance of the right ventricular free wall was studied,in the presence or absence of right ventricular hypertemsion in 13 open-chest dogs.The right coronary artery was perfused through a shunt from a carotid artery.Regional systolic shortening of the right ventricular free wall was measured by means of a sonomicrometric technique at various levels of coronary perfusion pressure.Regional shortening was insensitive to coronary perfusion pressure or flow when it was above 31 mm Hg or 0.27 ml/min per g.Once coronary perfusion was below this critical level, regional shortening in both base to apex and circumferential orientations decreased linearly, depending on the degree of perfusion pressure. Despite the presence of a monoexponential relationship between coronary perfusion pressure or flow and regional shortening, a direct linear relation between perfusion pressure and flow was consistently noted,with or without pulmonary artery banding,suggesting that there is limited autoregulation of right coronary flow.The critical perfusion pressure for maintaining regional myocardial function of the right ventricle was highly dependent on the level of right ventricular systolic pressure (r=0.64-0.72,P<0.05).Thus,right ventricular systolic pressure was one of the important determinants of regional wall motion during coronary underperfusion.